How to init flag with BF533


I am reading an exmaple code in VisualDSP++, and there is a function as below:

void Init_Flags(void)
FIO_ANOM_0311_INEN_W(0x0100);//*pFIO_INEN = 0x0100, workaround for anomaly 05000311.
FIO_ANOM_0311_DIR_W(0x0000);//For more information please refer to the comment header in file sys/05000311.h

And the description is :

Description: This function configures PF8 as input for edge sensitive 
                     interrupt generation. 
                     The switch connected to PF8 (SW7) can be used to change the //
                     direction of the moving light. 

But i do not know what is the meaning of FIO_ANOM_0311_INEN_W(0x0100). I think this is a function ? But i do not know where to find definication of this function ?